Pressure-sensitive or heat-sensitive recording material

Abstract

A pressure- or heat-sensitive recording material which, in its color reactant system, contains as a color developer for the color former, at least one substituted resorcinol compound of the formula ##STR1## or a corresponding zinc or aluminium salt, in which R is a carboxyl- or aroyl-free substituent which has a positive Hammett para-sigma value and which is capable of forming, together with the adjacent hydroxyl group, an intramolecular hydrogen bond in the form of a six-membered ring.

What is claimed is: 
     
       1. A pressure- or heat-sensitive recording material, which, in its color reactant system, contains as a color developer for the color former, a substituted resorcinol compound of the formula ##STR6## or its corresponding zinc or aluminium salt, in which R is selected from the group consisting of nitro, hydroxyamide, trifluoromethyl, formyl, lower alkanoyl, lower alkenoyl, lower alkanoyloxy, lower-alkoxycarbonyl, benzoyloxy, phenoxycarbonyl, benzyloxycarbonyl, lower-alkylsulfonyl, lower-alkylsulfonyloxy, phenylsulfonyl, phenylsulfonyloxy, lower-alkylphenoxysulfonyl, halogenophenoxysulfonyl, carbamoyl, sulfamoyl, N-(lower)alkylcarbamoyl, N-(lower)alkylsulfamoyl, N-phenylcarbamoyl, N-phenylsulfamoyl, N-hydroxy(lower)alkylcarbamoyl, N-hydroxy(lower)alkylsulfamoyl, phenylazo and phenylazomethine. 
     
     
       2. The recording material of claim 1, which contains as a color developer a metal-free resorcinol compound of the formula (1). 
     
     
       3. The pressure-sensitive or heat-sensitive recording material of claim 1, in which the compound of the formula (1) or the corresponding zinc or aluminium salt is present together with one or more other color developers. 
     
     
       4. The recording material of claim 1, in which the color developer has the formula (1) in which R is acetyl, carbomethoxy, carbethoxy, carbobenzyloxy, methylsulfonyl or phenylsulfonyl. 
     
     
       5. The recording material of claim 1, in which the color developer has the formula (1) in which R is carbomethoxy, carbobenzyloxy or phenylsulfonyl. 
     
     
       6. The recording material of claim 1, which is heat-sensitive. 
     
     
       7. The heat-sensitive recording material of to claim 6, which contains in at least one layer at least one color former, at least one color developer and, if desired, at least one binder. 
     
     
       8. The recording material of claim 1, which is pressure-sensitive. 
     
     
       9. The pressure-sensitive recording material of claim 8, which contains the color former dissolved in an organic solvent. 
     
     
       10. The pressure-sensitive recording material of claim 9, in which the color former is encapsulated in microcapsules. 
     
     
       11. The pressure-sensitive recording material of claim 8 in which the color former is encapsulated in microcapsules. 
     
     
       12. The pressure-sensitive recording material of claim 11, in which the encapsulated color former is present in the form of a layer on the back of a transfer sheet and the color developer of the formula (1) or the corresponding zinc or aluminium salt is present in the form of a layer on the front of a receiving sheet.